One street divides a single town that stands in two U.S. states.

This improbable contraption was passed down through five generations of industrious Tennesseans.

Mysterious library of an infamous financier and spiritual seeker.

More than five miles of underground passageways.

Live long and prosper in Tennessee.

The world's largest set of the ten commandments lay nestled in the heart of the Great Smoky Mountains.

The site of the Scopes Trial contains a small exhibit dedicated to the famous case.

One of the Cemestos prefab homes built to secretly house thousands of Manhattan Project workers.

The secret city built by the Manhattan Project.

A failed utopian experiment for British expats in the American South is now a Victorian village frozen in time.

This winding road of 318 curves is a must-visit for (careful) motorcycle and sports car enthusiasts.

One man has spent decades faithfully constructing this unique brick and cinderblock castle.

A 19th-century architectural wonder designed by the "father of the skyscraper."

The seat of Buffalo government is a gorgeous Art Deco palace.

This unique crypt designed by Frank Lloyd Wright for his longtime friend was not completed in either man's lifetime.

The absurd creation is a compulsory destination for selfies in Buffalo.

Rochester's signature culinary delicacy.

Canada's oldest railway tunnel is illuminated in a rainbow of color as it passes under the streets of this small city.

A castle built for love, and abandoned due to heartbreak.

This tiny little island has, as the name says, just enough room for its single house.

Where monkeys run wild and the humans are caged.

A mysterious castle built as a monument to lost love.

One of the world's largest automobile junkyards is a unique landscape of metal and moss.

Labor provided by Great Depression-era programs restored these 25,000 acres in Tennessee.